I am starting out with a 2.1 system since I'm in an apartment but looking to expand to full on 5.1 later. I work for a local retail store and have store discount on receivers from Pioneer Elite and Denon. I'm also interested in NAD too. Given I have not heard the Axiom's yet, what receiver would you guys recommended?

I agree with Doug, any of those choices will be fine, and contrary to what many believe, I don't believe an AVR will sound different from brand to brand. There are other characteristics which will produce a different sound, like speaker design and room acoustics.

I would say purchase the one that has the bells/whistles you like, and is within your budget.